The plates used are Solar Plates, which can be exposed to light through a printed transparency to etch into the plate. The medium is extremely sensitive to details, so it will pick up digital artifacts and pixellations and reproduce them. Here, I'm using a photograph and a sheet of transparent mylar to combine digital and physical media, offsetting this effect. I start out with a printed transparency of the image below, and overlay they mylar on top to react with the drawing overlaid on the photograph.

Next, we use small strips of solar plates exposed for different times to guage the appropriate exposure for the plates. Printing these plates helps us determine a final exposure time to get the full tonal range out of the image.

This one ended up near-perfect on the bottom of the hands, so we went with that time for the full plate.

After exposing the plate it's printed similar to an etching, which means pressing ink into the grooves, then wiping it off the surface. We soak the paper used in the process so that it physically enters the grooves on the plate, creating really nice lines.

I got a couple good results form this last session, but I plan on printing more with different colors and tints added. I'll add those to the project as they're completed.